1. Field
Example embodiments are directed to an image sensor using a photo-detecting molecule and a method of operating the same.
2. Description of the Related Art
A color image sensor is a photoelectric conversion device that converts light into an electric signal. A conventional image sensor includes a plurality of unit pixels arranged in an array on a semiconductor substrate. Each unit pixel includes a photodiode and a plurality of transistors. The photodiode generates and stores photocharges by detecting external light and the transistors output electrical signals according to the generated photocharges.
A complimentary metal oxide semiconductor (CMOS) image sensor includes a photodiode that receives and stores an optical signal. The CMOS image sensor also displays an image via a control device that controls or processes the optical signal. The control device can be manufactured using a CMOS manufacturing technique, and thus, the CMOS image sensor can be manufactured on one chip together with various signal processing devices.
A conventional CMOS image sensor outputs an amount of received light as a voltage, and the outputted voltage is read in a digital data by an analog-digital converter. Also, in order to measure charges generated in response to light, three or four transistors are required. Accordingly, it is difficult to form a single unit pixel on a sub-micron level.
In the conventional CMOS image sensors, as the pixel size is reduced, the photodiode area is further reduced, and thus, the sensitivity and dynamic range of the image sensors is reduced. Also, due to the diffraction of light, incident light cannot be focused on a single pixel but spreads to adjacent pixels, and thus, image resolution may be reduced.